Microsoft Security Response Center guidance
Vendor revision: Nov 14, 2026Release Notes
Vulnerability intelligence
CVE-2026-16240 and is rated Low severity with a CVSS score of 3.7. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
Use of externally-controlled format string in PostgreSQL pg_basebackup allows an attacker having already compromised a server to achieve disclosure from pg_basebackup memory, via backup manifest bytes. The vulnerability does not return the improperly-read bytes back to the attacker's server, so a successful attack would need separate implementation-specific secrets for that.
Integrity impact is unlikely; in particular, the applicable formatter does not support %n. Versions before PostgreSQL 18.7, 17.12, 16.16, 15.20, and 14.25 are affected.
Source: NVD